Search Results - "Duggal, B.P"

On (m, P)-expansive operators: products, perturbation by nilpotents, Drazin invertibility by Duggal, B.P.

“…A generalisation of -expansive Hilbert space operators ∈ (ℋ) [18, 20] to Banach space operators ∈ (𝒳) is obtained by defining that a pair of operators , ∈…”
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m-isometric generalised derivations by Duggal, B.P., Kim, I.H.

“…Given Banach space operators , ( = 1, 2), let denote (the generalised derivation) ) = ( − )( ) = − . If 0 ∈ σ ), = 1, 2, and if , then . For Hilbert space…”
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On Weak Supercyclicity I by Kubrusly, C.S, Duggal, B.P

“…This paper provides conditions (i) to distinguish weak supercyclicity from super-cyclicity for operators acting on normed and Banach spaces, and also (ii) to…”
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Moving Weyl’s Theorem from f (T ) to T by Rodríguez, M. Febronio, Duggal, B.P, Djordjević, S,V.

“…Schmoeger has shown that if Weyl’s theorem holds for an isoloid Banach space operator T ∈ B(X) with stable index, then it holds for f (T ) whenever f ∈ Holo…”
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Perturbations, Quasinilpotent Equivalence and Communicating Operators by Djordjević, Dragan S, Duggal, B.P, Živković-Zlatanović, S.Č

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Polynomially Meromorphic Operators by Duggal, B.P, Djordjević, Dragan S, Harte, Robin E, Živković-Zlatanović, Snežana Č

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Structure of elementary operators defining m-left invertible, m-selfadjoint and related classes of operators by Duggal, B.P., Kim, I.H.

“…We use elementary, algebraic properties of left, right multiplication operators to prove some deep structural properties of left m-invertible, m-isometric,…”
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Commutativity theorems for normaloid Hilbert space operators by Duggal, B.P.

“…Given Hilbert space operators A,B∈B(H), let δA,B(X)=(LA−RB)(X)=AX−XB and △A,B(X)=LARB(X)=AXB for all X∈B(H). The pair (A,B) satisfies (the Putnam–Fuglede)…”
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GENERALISED WEYL'S THEOREM FOR A CLASS OF OPERATORS SATISFYING A NORM CONDITION II by Duggal, B.P., Djordjević, S.V.

“…For a Banach space operator T ∈ B (X), it is proved that if either T is an algebraically, totally hereditarily normaloid operator and the Banach space X is…”
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On Weak Supercyclicity I by C.S. Kubrusly, B.P. Duggal

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Tensor product of n-isometries by Duggal, B.P.

“…A Hilbert space operator A is an m-isometry if ∑k=0m(-1)kmkA∗m-kAm-k=0. We prove that the tensor product of an m-isometry A with an n-isometry B is an m+n-1…”
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GENERALISED WEYL'S THEOREM FOR A CLASS OF OPERATORS SATISFYING A NORM CONDITION by Duggal, B.P., Djordjevic, S. V.

“…A bounded linear operator A ε B(X), X a Banach space, is heredetarily normaloid if, whenever M ⊆ X Is a closed invariant suspace of A, the restriction A|M of A…”
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A Putnam–Fuglede commutativity property for Hilbert space operators by Duggal, B.P., Kubrusly, C.S.

“…Given Hilbert space operators A,B∈B(H), define δA,B and △A,B in B(B(H)) by δA,B(X)=AX−XB and △A,B(X)=AXB−X for each X∈B(H). An operator A∈B(H) satisfies the…”
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ERRATUM TO "PARANORMAL CONTRACTIONS AND INVARIANT SUBSPACES" by Duggal, B.P, Kubrusly, C.S, Levan, N

“…In our paper "Paranormal contractions and invariant subspaces" published in Journal of the Korean Mathematical Society, Volume 40 (2003), Number 6, pp.933-942,…”
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Generalized Browder’s theorem for tensor product and elementary operators by Boasso, Enrico, Duggal, B.P.

“…The transfer property for the generalized Browder’s theorem both of the tensor product and of the left-right multiplication operator will be characterized in…”
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Bishop's property (β), a commutativity theorem and the dynamics of class A(s,t) operators by Duggal, B.P., Kubrusly, C.S., Kim, I.H.

“…Given a Hilbert space operator A∈B(H) with polar decomposition A=U|A|, the class A(s,t), 0<s,t≤1, consists of operators A∈B(H) such that…”
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Moving Weyl’s Theorem from f (T ) to T by Febronio Rodríguez, M., Duggal, B.P., Djordjević, S.V

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Hereditarily polaroid operators, SVEP and Weyl's theorem by Duggal, B.P.

“…A Banach space operator T ∈ B ( X ) is hereditarily polaroid, T ∈ HP , if every part of T is polaroid. HP operators have SVEP. It is proved that if T ∈ B ( X )…”
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BROWDER AND WEYL SPECTRA OF UPPER TRIANGULAR OPERATOR MATRICES by Duggal, B. P.

“…Let M C = ( A C 0 B ) ∈ B ( χ ⊕ χ ) be an upper triangulat Banach space operator. The relationship between the spectra of 𝑀𝐶and 𝑀₀, and their various…”
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ON OPERATORS WITH AN ABSOLUTE VALUE CONDITION by Jeon, In-Ho, DUGGAL, B.P

“…Let (equation omitted) denote the class of bounded linear Hilbert space operators with the property that $\midA^2\mid\geq\midA\mid^2$. In this paper we show…”
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